Raising chickens in city backyards may be increasing in popularity, as shown by the recent City of Toronto pilot project allowing backyard chickens in certain parts of the city. But for those intending to raise backyard chickens, a new research brief from Public Health Ontario (PHO) cautions that people should be aware of the risk of infectious diseases in these settings and of ways to protect against them.

“Raising chickens can provide benefits to families, but it doesn’t come without risks,” says Dr. JinHee Kim, a public health physician in environmental and occupational health at PHO and co-author of the research brief. “When we looked at the available research on this topic, we found that owners may have limited awareness of the health risks of contracting an infectious disease from backyard chickens and steps they can take to avoid getting sick.”

Salmonella or Campylobacter infections are the most commonly reported infections associated with backyard chickens and live poultry. Chickens and poultry can carry Salmonella in their intestines without showing symptoms of illness. The bacteria can also be found on the eggs of infected chickens and can be transferred onto feathers and the surrounding environment. People who pet or cuddle the chickens or touch contaminated items can accidentally ingest the bacteria, causing them to get sick.

Live chickens can also carry infectious bacteria, such as E. coli. In Ontario, a recent study testing for Salmonella and E. coli in the intestines of small flocks of chickens identified Salmonella in 0.3 per cent of 1,025 birds tested; E. coli was detected in 99 per cent of those tested.

Salmonella, Campylobacter and E. coli infections can be serious, particularly for those who are very young, elderly or with compromised immune systems. In some cases, hospitalizations and death can result from infections.

From 1990 to 2014, the U.S. Centers for Disease Control and Prevention (CDC) identified 53 outbreaks associated with Salmonella, with 2,630 individual cases related to live poultry contact. (There are no comparable data for Canada.) Keeping chickens inside households and kissing or cuddling birds were reported as some of the high-risk practices that led to infection.

Dr. Kim notes that practising some safety measures may reduce the risk of illness:

“For people who choose to raise backyard chickens, it’s important that they take measures to minimize the health risks. This is especially true for those most at risk of complications from getting sick,” says Dr. Kim.